Just the number. Let's leave out cash or cash equivalents, and also ignore assets like real estate that you own directly, or a personal business. So if you own a house, some shares in the total stock market mutual fund, some of the total bond market etf, 100 shares of APPL, some cash in a moneymarket fund, and some savings and checking accounts, I would count that as 3 different "investments". The ones that count are total stock market, total bond market, and APPL.
I'm sure you'll find some grey areas in that instruction. Just do your best.
EDIT: feel free to also leave out any investments so small that they all add up to 1% of the whole. That might give a more meaningful answer.